1. Field of Invention
The present invention relates to a cannulated tubular surgical grooved director with an integral side instrument guide configured to guide surgical instruments. The device may be used as a conventional tissue expander for orthopaedic or general surgery, and is particularly suited for use in accessing the carpal tunnel region during carpal tunnel syndrome procedures.
2. Background of the Invention
The use of a cannula, sheath, or director to guide or ease insertion of surgical instruments or to facilitate access to a surgical field is well known. With particular reference to the carpal tunnel syndrome, these devices are commonly used to facilitate the introduction of a balloon catheter that is serially inflated and deflated in the carpal canal during surgery to alleviate entrapment of the nerve.
Carpal tunnel syndrome is a common painful condition of the hand characterized by a decrease in median nerve sensibility with paresthesias of the fingers. It is the most common nerve entrapment syndrome of the upper extremity and results from compression of the median nerve in the carpal tunnel and its symptoms include nocturnal pain, clumsiness, and weakness of grasp or pinch.
The carpal canal is the area in the wrist and palm of the hand formed by the U-shaped cluster of bones of the carpus that forms the rigid hard floor and the two sides of the tunnel. Within the confines of this space are the median nerve, and the extrinsic flexor tendons of the thumb and fingers with their surrounding synovial membranes of the radial and ulna brusae. The roof of the tunnel is formed by the transverse carpal ligament on the palmar surface of the carpal bones. The ligament is attached medially to the pisiform and the hamulus of the hamate, and laterally to the tuberosity of the scaphoid and the medial part of the palmar surface and ridge of the trapezium. The proximal border of the ligament is partially merged to the distal border of the palmar carpal ligament, a more superficial structure separated from the transverse carpal ligament by the ulnar artery and nerve. The transverse carpal ligament is attached to the palmar aponeurosis, which lies superficial, and contributes crossed oblique fibers to the deep surface of the aponeurosis.
Any condition that diminishes the size of the carpal tunnel can precipitate the carpal tunnel syndrome. Repetitive wrist and hand motions can cause thickening and hypertrophy of the transverse carpal ligament. Proliferation of synovium from normal wear and tear of daily activities can cause compression of the median nerve within the closed confines of the carpal tunnel. Furthermore, systemic conditions such as pregnancy, obesity, diabetes mellitus, thyroid dysfunction, or chronic renal failure can initiate the syndrome. Generally, the syndrome occurs most often in patients between the ages of 30 and 60 years and is five times more frequent in women than in men.
Failure to correct the condition in a timely manner ultimately results in irreversible muscle damage, as indicated by denervation potentials.
Historically, carpal tunnel syndrome has been treated nonsurgically by splinting of the affected hand and wrist, oral anti-inflammatory medication, and local steroid injection. Where nonsurgical methods are unsuccessful, surgical intervention is necessary.
Open surgical decompression of the carpal tunnel by division of the transverse carpal ligament was first described in 1930 by Learmonth. Open surgical procedures generally entail a curved longitudinal incision to the ulnar side and parallel to the thenar crease. Another open procedure angles the incision towards the ulnar aspect of the wrist which helps to avoid cutting the palmar sensory cutaneous branch of the median nerve. After dissection of the skin and subcutaneous tissue, the transverse carpal ligament is identified and divided along its ulnar border to avoid and to prevent injury to the median nerve or its recurrent branch.
Open surgical decompression of the median nerve is not without risks and complications. Long term analysis of patients who have undergone surgical treatment for carpal tunnel syndrome have shown a failure rate as high as 19% (Kulick, Michael, I., D.D.S., M.D., et al.; Jour of Hand Surg; 11A (1):59-66. 1986). Thirty percent of all patients in one study were rated with poor after fair result at an average of 5.5 years follow-up; “57% of the patients in the study complained of return of some preoperative symptoms, most commonly pain, beginning an average of 2 years after surgery.” (Nancollas, Michael P.; Symptoms may return after carpal tunnel surgery; JAMA; Vol 265, No 15, p 1922, Apr. 17, 1991.) Complications include continued pain and or numbness, hypersensitive scar, loss of grip strength, joint stiffness, adherence of flexor tendons, neuroma, injury to the median nerve or its motor branch or digital nerve injury, damage to the palmar cutaneous nerve, vascular injury, palmar hematoma, infection, and possible reflex sympathetic dystrophy.
A retrospective analysis of 40 cases of reoperation for carpal tunnel syndrome found adhesions and fibrosis around the median nerve in the carpal canal in 36 cases. (Wadstroem, J., Nigst, H.; Reoperation for carpal tunnel syndrome: a retrospective analysis of 40 cases; Ann. Chir. Main; 5:54-58, 986.)
Hand weakness with loss of grip strength can also be a problem. Carpal tunnel release produces an average widening of the transverse carpal arch of 2.7 mm. There is a direct relationship between widening of the carpal canal and decreased grip strength. The average decrease in grip strength is 12%. (Gartsman, Gary, M., Kovach, John, C., et al.; Carpal arch alteration after carpal tunnel release; J. Hand Surg. (AM.) 11-A:372-374, May, 1986.) Computerized tomographic (CT) studies of the carpal tunnel after transection of the transverse carpal ligament have shown that if the flexor retinaculum is not intact, the flexor tendons will bowstring palmarly when the wrist and fingers are flexed together, causing weakness of grip. Some authors have recommended the use of a firm postoperative compression dressing immobilizing the wrist in slight dorsal extension for 3 weeks to prevent prolapse of the flexor tendons. (Jessurun, W, Hillen, B, et al.; Carpal tunnel release: Postoperative care: Handchirurgie 20:39-40, January, 1988.)
Because of the concern over widening of the carpal arch with subsequent decrease in grip strength, following standard carpal tunnel release, Jakab and associates devised a technique employing reconstruction of the transverse carpal ligament. (Jakab, Emery, Ganos, Doreen, et al.; Carpal tunnel release: Postoperative care: Handchirurgie 20:39-40, January, 1988.) These authors learned that by reconstructing the transverse carpal ligament, the transverse carpal arch was stabilized affording protection to the median nerve and preventing potential bow-stringing of the flexor tendons. By repairing the transverse carpal ligament the normal relationship of the carpal canal and its contents was restored and maintained.
Pre and post-operative CT scanning of the wrist in carpal tunnel syndrome has been performed and has shown that postoperative decompression results in the regeneration of a much more flexible ligament, which allows the contents of the tunnel, to expand anteriorly. The divided transverse carpal ligament heals in a stretched or arched position allowing more room for the median nerve and flexor tendons. (Chaise, F., Roger, B.; Pre- and post-operative CT scanning of the wrist in carpal tunnel syndrome; Rev Chir. Orthop.; 72:297-302′ 1986.)
In recent years endoscopic techniques have been utilized to incise and divide the transverse carpal ligament. Attempts have been made to decrease the size of the surgical incision with the benefit of decreasing postoperative complications because hand strength returns quickly and the hand is less tender.
Refinements of endoscopic release of the carpal ligament are evolving but complications with this procedure have been reported The complications include neuropraxia of the median and or ulnar nerve, digital nerve laceration, laceration of palmar vessels, laceration of flexor tendons, neuropraxia or laceration of the palmar cutaneous branch of the median nerve, palmar hematoma, adhesions of tendons, perineural fibrosis, bowstringing of flexor tendons with loss of grip strength, incomplete transsection of the carpal ligament with recurrence of symptoms and hypertrophic scar.
U.S. Pat. No. 5,179,963 issued Jan. 19, 1993 to the present inventor solves these aforementioned complications and employs a balloon catheter device with a separate nerve protector inserter and pressure gauge monitor. The balloon catheter is inserted percutaneously and is utilized to dilate and expand the transverse carpal ligament, through serial applications of fluid pressure while it is moved along the carpal tunnel, thereby increasing the diameter of the carpal tunnel, relieving compression of the median nerve and alleviating the symptoms of carpal tunnel syndrome. Percutaneous dilatation of the transverse carpal ligament increases the spatial diameter of the carpal tunnel, thereby relieving pressure on the median nerve in the hand and wrist without the surgical and treatment problems previously discussed.
U.S. Pat. No. 5,545,136 issued Aug. 13, 1996, also issued to the present inventor, discloses a surgical instrument used in the treatment of carpal tunnel syndrome having a rigid tubular member with lumen through which a balloon carpal tunnel plasty procedure may be undertaken. The balloon expands through an aperture in the radial wall of the tubular member and the tubular member includes a rigid, solid rounded tip to ease insertion of the apparatus into the carpal tunnel. Other instruments are then used in conjunction with the instrument to perform the surgery.
U.S. Pat. No. 6,706,069 issued Mar. 16, 2004, also issued to the present inventor, is directed toward a grooved director with a built in balloon which is inflated by a pump to a predetermined pressure to expand the walls of a collapsed vertebra. The device is inserted into the body of the compressed vertebra and the grooved director is positioned and aimed in a direction under the compressed superior end plate of the vertebral body. The balloon inside of the grooved director is inflated and the force and direction of balloon inflation restores the height of the fractured vertebrae. The balloon is deflated and the grooved director is circumferentially rotated while intermittently inflating and deflating the balloon to create a symmetrical space within the center of the vertebral body. The balloon is deflated and the grooved director device with balloon is removed leaving a rebuilt vertebra which may be filled with a biocompatible material.
U.S. Pat. No. 4,655,214 issued Apr. 7, 1987 shows a soft inflatable sheath having a closed rounded distal tip that is inserted through a catheter and inflated adjacent the distal tip of the catheter prior to intubation. The proximal end of the sheath is sealed to maintain it in an expanded condition when the catheter is being intubated. Following intubation the cylindrical sheath is deflated and withdrawn. U.S. Pat. No. 4,645,491 issued Feb. 24, 1987 shows a catheter placement apparatus used in inserting a catheter to a preferred depth. The device comprises a surgical needle provided with a thin-walled transparent polytetrafluoroethylene tube which is heat shrunk over the stem portion of the needle to form a longitudinal window allowing a catheter inserted in the needle to be viewed. The catheter has a colored patch of the same length as the window and a series of spaced circular bands of differing colors allowing the position of the catheter to be accurately located by lining the colored patch with the window and advancing the catheter until at least one band appears in the window. The color and distance of the band nearest to the surface of the patient's skin are used to determine the position of the catheter. The surgical needle is withdrawn by sliding it along and off the catheter. U.S. Pat. No. 2,164,926 issued Jul. 4, 1939 shows a catheter stylet with an eye or aperture positioned on an opposite lateral wall behind the tip. U.S. Pat. No. 3,537,452 issued Nov. 3, 1970 shows a needle guard and beveled cutter for use with intravenous catheterization units. The device has a tubular body with a flat base and a longitudinally slotted top. The diameter of the tube is greater than the diameter of the needle contained therein. U.S. Pat. No. 3,592,193 issued Jul. 13, 1971 shows a removable needle guide used with a flexible catheter tube in withdrawing or introducing fluids relative to a body. The hollow tubular needle guide has a sharpened needle portion provided at its proximal end for puncturing the skin, tissues and veins of the body where the needle is inserted. At its distal end, the guide has winged handles which provide controlled insertion and removal from the body with subsequent attachment from a flexible catheter tube. U.S. Pat. No. 5,011,478 issued Apr. 30, 1991 shows an introducer set including a sheath and dilator formed with a smooth external shape. The distal end of the sheath is embedded in the dilator and formed in angle oblique to the longitudinal access of the introducer set. U.S. Pat. No. 3,559,643 issued Feb. 2, 1971 shows a catheter placement unit for insertion of a catheter into a body lumen through an incised opening in the lumen wall. The unit includes a longitudinally slit sheath having a catheter therein and an advancer connected to one end of the catheter, initially in axial alignment with the sheath to close the end of the sheath.
There is presently a need, however, for an orthopedic and general surgical director instrument that combines various features of multiple instruments. When carpal tunnel release procedures are undertaken as described above, an instrument similar to known elevator devices is needed to extend the reach of the surgeon into the confines of the operating field and facilitate elevation, retraction, cutting and/or manipulation of the tissues therein. Particularly regarding the surgical carpal tunnel intervention described supra, the instrument of the present invention is uniquely combined with a balloon catheter mounted within its hollow interior so that its balloon may be deployed from a protected window in the distal portion of the instrument and a surgical knife may be deployed via the side guide rail to cut tissue as needed.